Line transposition bracket with reinforcing gussets



Oct. 13, 1953 LINE TRANSPOSITION BR Filed June 21, 1951 R. cAsE ACKETWITH REINFORCING GUSSETS 2 Sheets-Sheet l I I I 1 [Mi/V7013 @gyefs Casea, qxwamza 41% Oct. 13, 1953 R. CASE 2,655,553

LINE TRANSPOSITION BRACKET WITH REINFORCING GUSSETS Filed June 21, 19512 Sheets-Sheet 2 [NM/Wag @WSIZS' Case Patented Oct. 1 3, 1953 UNITEDSTATES PATENT OFFICE LINE TRANSPOSITI REINFORCI ON BRACKET WITH NG'GUSSE'I'S Rogers Case, Orange, N. J Application June 21, 1951,Serial-N0. 232,738 6 Claims (01. 174-147) This invention relates to abracket for transl posing paired line wires of communication lines.

Specifically considered the disclosure herein relates to an improvementin the brackets disclosed in my issued Patents No. 2,455,228, datedNovember 30, 1948 and No. 2,455,229, dated Noplained in those patents,it is a matter of necessity in the more efficient systems of longdistance electrical communication along wires that paired wires betransposed at intervals by crossing them and the brackets disclosed inthose patents are constructed easily and accurately to effect suchtransposition. Also as explained in those patents, it is of greatassistance in making the transposition that the insulators on which: thewires are trained be mounted rotatably in four outwardly open clevisesin which the insulator pins are supported.

In service there is a very substantial pressure of the wires against thestructure of the brackets and such pressure creates the problem ofproviding brackets of adequate strength with economy in-the weight ofmetal included in the bracket and the provision of brackets so light asto facilitate their installation in the line.

The object of my invention is therefore to provide transpositionbrackets primarily in accordance with the disclosure of the above-notedpatexert a maximum resistance to the stress-creating thrust of the wirestransposed by the bracket in conjunction with themclusion of a minimumweight ofmetal in the bracket.

2,455,228, which is a bracket ofthe: span ty That is, it is purposedparticularly for insertion in an electrical line between the line:poles. As indicated above, the improvement ofthis invention is equallyapplicable to the bracket of my prior Patent No. 2,455,229; which ispurposedpa-rticularly for direct mounting on the cross arm of a linepole.

In the accompanying drawings; illustrativeof one embodiment ofmyinvention:

2 Fig. I is a plan view of myimproved transposition bracket.

Fig. II is across sectional View taken in the plane of the section lineII-II of- Fig. I and looking toward the upper edge ofthe sheet ofdrawmgs.

rig. III is an end elevation of the bracket frame structure as seen atthe lower larly extended leg 70.

Clevises8=and 9: bear respectively the same relation to the end reach 2as do clevises 7 and 6 to end'reach I.

or' conversely rising seen that insulator ga ses from the lower fork ofclevis to the upper fork of clevis I.

Spool-form insulators Ni, H, 12 and i3 are mounted respectively inclevises t, l, 8 and 8. Desirably as is shown in the drawings, insulatorpins M are of such form that the insulators are freely rotatable onthem. These insulators which are of primarily spool-form and which maybe composed of glass, porcelain, rubber, fiber or plastic composition orother material having suitable physical and electrical-insulatingproperties are carried each by its insulator pin I l which has a head14a resting on and a shank Mb which projects below the underfork of theclevis. Su'table means for engaging the insulator pin in the clevis inwhich it is mounted is shown as a cotter pin ldc, but such engagementmay be provided by means of a nut having threaded engagement with theprojecting end of the pin or by any other suitable engagement.

In the arrangement of the insulators it will be it has itswire-receiving groove ltd above the base, or median, plane of thebracket frame and that the wire-receiving groove Ila of insulator itlies below the base, or median, piane of the frame. The wire-receivinggrooves of insulators l3 and i2 are in vertical alignment with thewire-receiving grooves of insulators it and II respectively.

It will be seen that the arrangement of the clevises and insulatorsmounted in them is diagonal. Thus the high clevises B and t are diagtheupper fork of the clevis onally opposite each other in the bracketassembly and the low clevises l and 8 similarly are diagonally oppositeeach other. As viewed in the drawings, the high and low clevises, andinsulators mounted in them are staggered relatively in the bracket. Thisarrangement conforms to the crossing of line wires within the bounds ofthe bracket frame. Together with the fact that all the clevises openoutwardly of the frame structure, it conforms the paired line wires onthe insulators of the bracket without interrupting the span ordisassembling the bracket.

In the relation of the paired line wires with the bracket, the wire A isshown as trained on the low insulators II and i2 and the wire B is shownas trained on the high insulators la and 13. In their crossed relationthe two wires are spaced vertically a distance equal to the distancebetween the wire-receiving grooves of the diagonal pair of highinsulators and the wire-receiving grooves of the diagonal pair of lowinsulators, as for example the vertical distance between thewire-receiving grooves Ba and i la. in Fig. I of the drawings. Becausethe insulators are mounted in the clevises, the wires trained on theinsulators in their wire-receiving grooves are confined within theclevises. There is therefore no likelihood that there will be a floater,that is an upwardly escaped wire, if an insulator should be broken inservice.

i The entire frame structure of the bracket being a one-piece castingpossesses in a very high order the properties of rigidity, strength andendurance. The clevises being integrated in the frame structure bycasting, there are no bolts or rivets to shear or work loose in serviceand the insulator pins are supported in clevises which minimize springor other relative movement between parts or regions of the structure.The insulator pins are thusprotected against the thrust to the operationof threadin V Of these I have found aluminum alloy to be of the linewire on the insulators which are mounted on them.

As to the vertical spacing between the line wires in their crossedrelation, that vertical spacing is modified by deflecting the lower forkof each of the clevises for the high insulators slightly below the baseplane of the frame and by elevating the upper forks of the clevises forthe low insulators slightly above the base plane of the frame. Thiaccommodation in the organization of the frame permits the use ofinsulators having a desirable structural contour while obtaining adesired spacing of the wires. That is, a de sirable form of insulatorhaving been selected, the frame of the bracket can be cast to give adetermined vertical spacing of the crossed wires while using insulatorsof the specific selected form, by casting the one-piece frame with theforks of its clevises deflected appropriate distances from the baseplane of the frame.

As indicated above, it is desirable that the bracket as described beintegrally cast of one of the light metals such as aluminum or an aluamagnesium alloy.

preferable. Also as above indicated, I have found that a slightadditional mass of metal placed most advantageously in the structure ofthe bracket adds stress resistance far out of proportion to the addedweight.

Such reinforcement consists of relatively thin, triangular ribs orgussets integrated between the median or base portions of each of theend reaches l and 2 of the bracket and along the adjacent surfaces ofthe longer angularly extended legs of the clevis-forming portions ofthose reaches. These triangular gussets I5 and it have relatively longfree edges Mia and Zila so that they each integrate with the medianportion of the reach and one of the angularly extended legs of a clevisthroughout the major proportion of the length of those members. Thegussets l5 and as have their edges approximately parallel so that withminum alloy, magnesium or the included median portion of the reach, theyform an approximately rhombic reinforcement extended between andintegrated with the angularly extended legs of the clevis. As shown inFig. II of the drawings this gusset structure comprising gussets l5 and28 extends between the inner face of leg to of outwardly open clevis 6and the inner face 10 of outwardly open clevis '5. Similarly, as shownin Fig. III of the drawings with respect to reach 2 of the bracket,gussets It and H are arranged with their free edges its and l'iaapproximately parallel and with the gusset structure standing betweenangularly extended leg 8c of outwardly open clevis 3 and leg ofoutwardly open clevis 9. As with the gusset structure made part of reachI, each of gussets l6 and I! is integrated with the median portion 5 ofthe reach.

This relatively small mass of metal because of its position and itsintegration with the fundamental structures of the bracket, presents amaximum opposition to the thrust of the line wires transposed by thebracket and thus counteracts the stress-creating effects of such thrust.It has been found by test that the regions in which the stresses causedby the thrust of the wires are concentrated in a bracket lacking thisreinforcement are adjacent the corners at which the forks of theclevises join the median portions of the reaches and particularlyadjacent the junction of bracket structure to the same specific metal ason the tests is as follows:

addition of the gusset structures jfailui'e takes place only atmuchhighe'r load and at the holes I pins 'or adjacent such holes in theend reaches 3 and I of the bracket, It is to he understood that withoutsuch reinforcement the bracket as cast from a suitable aluminum al- ,loy is amply able to sustain the. henna load im' posed by the line wires,which is about 2000 pounds. The reinforcement provided by the gussetstructure does, however, give increased assurance against bracket'failu' eunder the exigencies of continuedservice. V Also, thereinforcement to the brackets gives assurance against disruption of Vthe line by bracket failure under abnormal eonditions, such asunus'ually high wind pre'ssures and abnormal accumulations of ice on thebrackets.

To determine the resistance of the fundamental load imposed by the linewires and to show comparatively the increase in such resistance obtainedby adding the gusset for the insulator structure of this invention,tests were made on three types of the bracketas follows:

, Typ e A.Thisbracket was integrallycast from a suitable aluminum alloy,which metaispec ficaily was Alcoa 356T6 -alloy. It was close to theexact disclosure of Patent No. 2,455,228 comprising no reinforcinggussets as herein disclosed.

Type B.- This bracket was made of the same alloy as the type A bracket,and in its initial'stru'cture corresponded exactly to that bracket. Thistype B bracket was, however, reinforced by gussets shaped and arrangedas herein disclosed. Those gussets were welded to thelongerangular'lyextended legs of the clevises and to the median or baseportions of the side reachesof the bracket.

Type (IQ-This bracket was identical with the specific disclosure herein,with the reinforcing gussets cast integrally with the fundamentalstructure of the bracket. It was composed of the the type A and type Bbrackets. o.

The fundamental structure of the type 'B bracket, like the type Abracket was obtained by permanent mold casting, and the entire structureof the type C bracket includingthegussets was obtained by permanent moldcasting as'an initially integral structure. v type B, primarily becausethe manufacture of the bracket is simplified by eliminating the stepof\llelding- For loading the brackets, the Baldwin -southwark 300,000pound testmachinejwas used. in place of the standard-glassinsulators. aluminum replacements were used because it wasfound that theglass insulators failed before any damageoccurred to the brackets. TwoA; inch steel'cable of approximately 8 foot length were attached tosteel bars with theproper line spacing for jthe brackets to be testedand the cable tension was 6 equalized by pivoting the upper bar at itscenter. The lower bar was pivoted at its center so that it was free tomove in the opposite plane allowingthe cables "to twist if the'loading'resulted in that type of moment. The loading of all three brackets wascarriedto destruction. The data Weight, Loadat Type pounds pounds Per COthe.

Type C is preferred to failure,

they may be rotatable "the said longer and shorter economical to providefor the formation of the gussets in the permanent mold than to make suchgussets separately and to weld them into place after casting.

Whereas the primary intent of my invention is to reinforce thefundamental structure of a transposition bracket frame made by thepermanent mold casting of one of the light metals and by strengtheningsuch frame to decrease the total weight of metal desirably included inthe bracket, my invention maybe utilized in brackets which are of thesame form but which are difierently made. Thus gussets of the same shapeas above described may be integrated in re same described positions in abracket of the same described shape and structural arrange-- ment butwhich is fabricated of steel or other suitable metal instead of beingintegrally cast. In such brackets the gussets by reinforcing thestructure of the bracket frame, serve similarly to reduce the totalweight of metal necessarily or desirably included in thebracket.

As used herein the terms vertical. lower. and the like refer to what maybe considered the normal position of the bracket in a line the wires ofwhich aretransposed by the bracket ina'ccordanc'e with preexistinggeneral practice. It is to be understood that the insulators either mayrotate-on their pins, in the clevises or'both the pins and theinsulators may be rotatable with respect to each other -andto the framestructure of the bracket.

Having ttion, it is in the statement-of the claims appended hereto.

I claim as my invention: 1. A wire-transposingbracket adapted for thecrossing of paired line wires comprising a frame integrally cast fromtral base region to provide four outwardly'open insulator-mountingclevises, the longer and shorter legs of the clevises'ofeach said reachbeing oppositely arranged and the arrangement of ing clevises inthebracket frame, two-reachesint ereonnecting the said two forkedreaches, 'spoolf form insulators having circumferential'wire receivin'ggrooves r'otatably mounted in'thesaid of, 'said two gussets ofeach'sai'd reach being tively to each other to provide reinforcement inthe structure of the bracket frame and composite stress resistanceagainst the load imposed by wires transposed by the bracket.

terconnecting the said 2. In a wire-transposing bracket adapted for thecrossing of paired line wires, a frame integrally cast from a lightmetal selected from aluminum, magnesium and their alloys and having twogenerally parallel reaches terminally forked at both ends of each bymeans of longer and shorter legs angularly extended from a central baseregion to provide four outwardly open insulator-mounting clevises, thelonger and shorter legs of the clevises of each said reach beingoppositely arranged and the arrangement of the said longer and shorterlegs being reversed in the said two forked reaches to give a diagonalmatching of higher and lower insulator-mounting clevises in the bracketframe, two reaches interconnecting the said two forked reaches; and

.two strengthening gussets extended between and integrated with thelonger legs of the said clevises of each forked reach and adjacentsurfaces of the said base region thereof, said two gussets of each saidreach being arranged in an approximately diagonal line relatively toeach other to provide reinforcement in the structure of the bracket.frame and composite stress resistance against the load imposed by wirestrained on insulators mounted in the said clevises and transposed by thebracket.

3. A wire-transposing bracket adapted for the crossing of paired linewires comprising a frame integrally cast from a light metal selectedfrom aluminum, magnesium and their alloys and having two generallyparallel reaches terminally forked at both ends of each by means oflonger 7 and shorter legs angularly extended from a central base regionto provide four outwardly open insulator-mounting clevises, the longerand shorter legs of the clevises of each said reach being oppositelyarranged and the arrangement of the said longer and shorter legs beingreversed in the said two forked reaches to give a diagonal matching ofhigher and lower insulator-mounting clevises in the bracket frame, tworeaches intwo forked reaches, spoolform insulators havingcircumferential wire-receiving grooves rotatably mounted in the saidfour clevises; and two strengthening gussets extended between the longerlegs of the clevises of each forked reach and adjacent surfaces of thesaid base region thereof and cast integral therewith, said two gussetsof each said reach being arranged in an approximately diagonal linerelatively to each other to provide reinforcement in the structure ofthe bracket frame and composite stress resistance against the loadimposed by wires transposed by the bracket.

4. In a wire-transposing bracket adapted for the crossing of paired linewires, a frame integrally cast from a light metal selected fromaluminum, magnesium and their alloys and having two generally parallelreaches terminally forked at both ends of each by means of longer andshorter legs angularly extended from a central base region to providefour outwardly open insulator-mounting clevises, the longer and shorterlegs of the clevises of each said reach being oppositely arranged andthe arrangement of V the said longer and shorter legs being reversed inthe said two forked reaches to give a diagonal matching of higher andlower insulator-mounting clevises in the bracket frame, two reaches in-'longer legs of the terconnecting the said two forked reaches; and twostrengthening gussets extended between the longer legs of the saidclevises of each forked reach and adjacent surfaces of the said baseregion thereof and cast integral therewith, said two gussets of eachsaid reach being arranged in an approximately diagonal line relativelyto each other to provide reinforcement in the structure of the bracketframe and composite stress resistance against the load imposed by wirestrained on insulators mounted in the said clevises and transposed by thebracket.

5. A wire-transposing bracket adapted for the crossing of paired linewires comprising a frame having two generally parallel reachesterminally forked at both ends of each by means of longer and shorterlegs angularly extended from a central base region to provide fouroutwardly open insulator-mounting clevises, the longer and shorter legsof the clevises of each said reach being oppositely arranged and thearrangement of the said longer and shorter legs being reversed in thesaid two forked reaches to give a diagonal matching of higher and lowerinsulator-mounting clevises in the bracket frame, two reachesinterconnecting the said two forked reaches, spool-form insulatorshaving circumferential wire-receiving grooves rotatably mounted in thesaid four clevises; and two strengthening gussets extended between andintegrated with the said clevises of each forked reach and adjacentsurfaces of the said base region thereof, said two gussets of each reachbeing arranged in an approximately diagonal line relatively to eachother to provide reinforcement in the structure of the bracket frame andcomposite stress resistance against the load imposed by wires transposedby the bracket.

6. In a wire-transposing bracket adapted for the crossing of paired linewires, a frame having two generally parallel reaches terminall forked atboth ends of each by means of longer and shorter legs angularly extendedfrom a central base region to provide four outwardly openinsulator-mounting clevises, the longer and shorter legs of the clevisesof each said reach being reversed in the said two forked reaches to givea diagonal matching of higher and lower insulator-mounting clevises inthe bracket frame, two reaches interconnecting the said two forkedreaches; and two strengthening gussets extended between and integratedwith the longer legs of the said clevises of each forked reach andadjacent surfaces of the said base region thereof, said two gussets ofeach said reach being arranged in an approximately diagonal linerelatively to each other to provide reinforcement in the structure ofthe bracket frame and composite stress resistance against the loadimposed by wires trained on insulators mounted in the said clevis andtransposed by the bracket.

ROGERS CASE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName 7 Date 2,261,597 Sutherland Nov. 4, 1941 2,455,228 Case Nov. 30,1948

